Heretofore steam generating apparatus had taken the form of relatively large floor-supported units that were housed at a location remote from the shower or other steam room, such as in a closet, an attic or a basement. The unit provided, through an elongated steam line or hose, a supply of live steam into the room. The line could be quite long, such as 50 feet, which would result in substantial heat loss. The user might have to control the unit from the unit itself at the remote location. Further, the unit would take up space and could not be put too close to certain structure or objects because of the high temperature of the boiler of the unit.
The control of such unit was generally very basic, in that the user-set temperature was generally maintained, but it was based on monitoring and then turning the steam generator on and off in reaction to changes in the room temperature, which resulted in noticeable cyclical fluctuations in temperature above and below that set temperature. Also the sound of the heat generation going on and off were noticeable and made the temperature variations more noticeable. This lack of a constant temperature and sound level detracted from the tranquility and enjoyment of the steam room.
Another problem encountered by use of such units was fogging over of mirrors in the shower or steam room. Various defogging mirrors have been used, but they were costly, complex or both. One prior art attempt to solve the problem is illustrated in U.S. Pat. No. 4,150,869 which discloses a special apparatus that caused heated water or steam to flow continuously over the rear of a shower mirror to warm it. A similar approach is disclosed in U.S. Pat. Nos. 4,993,821, 4,836,668, 4,557,003, 4,904,072 and 5,032,015. U.S. Pat. No. 4,076,374 discloses a device which uses a continuous flow of heated water over the front face of the mirror. Such an arrangements are also subject to clogging and other maintenance problems associated with flow devices. U.S. Pat. Nos. 3,708,218 and 4,556,298 disclose devices that run heated water through special coils located behind the mirrors.